1. Field of the Invention
This invention relates to cross platform programs, and more specifically to objects used within such programs that contain variables that become defined for a specific operating system environment.
2. Background and Related Art
An installer program is a software program that enables a programmer to write specific code that will allow a user to install a given application program onto the drives of a computer in a way that enables the given application program to work correctly with the computer's environment including its operating system. There are several types of installers--Java installers and operating system specific installers, e.g., Windows installers, OS/2 installers and AIX installers, etc. Many of these install programs existing today have various limitations in their functionality as discussed below.
One type of Java installer is provided by a software company known as InstallShield. Currently, this Java installer has some limitations on certain functional features. For example, the Java installer provides default panels, but the text can't be changed or configured. Also, this Java installer is not easy to customize. In other words, a programmer cannot easily add a function to the installer program that it doesn't already do. In addition, the Java installer does not provide very much registry support. A registry is a central repository for all possible information for the computer such as hardware configurations and software settings, etc. The registry enables a user/programmer to keep information about the software product. It enables a user to find out information about other products, based upon what the user/programmer put into the registry or what the user is looking for. Presently, the Java installer only works with a Windows' registry; and the support provided here is limited. For example, it does not enable the system Windows' registry to be updated directly. Instead, the keys to be updated are in a file which must be imported into the registry through a system call. It would be desirable if such a Java installer program supported multiple directories, splash screens (which are images that come up while a software product is being installed), and multiple languages instead of just English. Furthermore, it would be desirable for a given installer program to be more broadly applicable to other environments and operating systems. Although InstallShields' Java installer is tailored to Java, it is also geared somewhat for the Windows' operating system as discussed above in terms of the Windows' registry support provided. However, it does not provide specific support for other operating systems such as OS/2 or AIX.
Another Java installer is called "Install Anywhere" from ZeroG. This Java installer program also has a default panel that cannot be changed, i.e., it is not customizable in terms of the order in which the panels are to appear. Likewise, registry support is limited. A user/programmer updates a registry from a file using a "reg_edit" command. Although this installer program enables a user/programmer to add a few items into the registry, the registry cannot be queried. In addition, other registry functional features are not available. Likewise, there is no multiple directory support, and no national language support. Also, it does not support multiple operating systems, i.e., there is no OS/2 or AIX specific support.
Another approach would be to provide install APIs for Java. However, this approach is not yet available.
With respect to operating system specific installers, InstallShield provides a Windows' 32 installer. Although this installer program is widely used throughout the industry, it is based upon a proprietary scripting language that InstallShield defined. The scripting language is similar to Basic programming language. Nevertheless, a user/programmer must learn the scripting language to be able to write an install program, and it is not a real easy language to write in. When creating install programs using the Windows' 32 installer, a programmer must first learn the new language. Even then, it is difficult to write complicated install scripts with this scripting language.
For the OS/2 operating system, there is not a true architected way within the operating system itself to install. Two programs have existed for writing install code on OS/2. One of them is "Feature Installer", which has a tendency to be difficult to use. Also, it is hard to figure out how to write an install program from it. For example, it is tied into the workplace shell which requires special knowledge of SOM programming. Also, there is no compression of files. The second program is "Software Installer", which was the precursor to "Feature Installer", and is no longer supported as a product.
Also, for the OS/2 operating system, since OS/2 has Java on it, a programmer could use InstallShield's Java edition to write install code to install some types of programs. However, this does not provide much function other than just copying files.
Other than using Feature Installer, Software Installer, or a Java Installer, programmers must come up with their own way to write install code for an application program on an OS/2 machine.
Since the OS/2 operating system appears to have been architected without regard to install features, the above discussed ways for installing OS/2 application programs have no way to talk to each other. They will each have a different way of keeping track of things. As such, there is no one place to go to find out what has been installed on an OS/2 machine or to check dependencies to see what has been installed already.
For the AIX operating system, the command "installp" is used to install products. It is platform specific. It is also command line driven which is typical for the AIX operating system. Nevertheless, it appears to work well and is widely used.
As shown above, installers are tailored for a specific operating environment, e.g., JAVA, and/or operating system. As such, programmers using an installer to write install code must know and understand the specific operating environment and/or system quite well. This creates an added burden for a software company that produces many different application programs, with each application program available on many different operating systems. Separate install code must be written for each application for each different operating system. This requires a matrix of expertise--expertise in a given application, and expertise in a given operating system environment. This requires either a widely knowledgeable expert who is burdened with writing various specific versions of install code, or many different expert programmers who are essentially assigned the same task of writing install code.
Without such expertise, small software products just do not get install programs written for them for various platforms. Furthermore, money, resources, and time could be saved by writing an installer program only once that is applicable across all operating systems and environments.
It would also be desirable for a software manufacturer to have a common look and feel for writing install code for all of its products. In this way, as a programmer moved from platform to platform in writing install code, the programmer would recognize the interface, and know how it works. Thereby making the programmers task much easier.
Also, as shown above, there presently does not exist a functionally rich installer for Java. It is desirable to have a Java installer that is at least as functionally rich as a Window's installer.